The messenger RNA (mRNA) of a responder cell strain is synthesized more rapidly when cells are maintained in the presence of DPH than in the absence of the drug. Preliminary data suggests that mRNA also may be degraded more rapidly when cells are grown in medium contaning DPH. The latter experiments are being repeated with the addition of glucosamine in order to produce a more efficient chase period. mRNA is being translated in a cell free protein synthesizing system derived from reticulocytes in order to quantitate the functional mRNA. Immunoprecipitation will be used to quantitate functional type I pro alpha chain mRNA.